This invention relates to an improvement in a weft detaining device for a shuttleless loom, of the type wherein a certain length of a weft yarn required for each weft picking is detained prior to a weft injection through a weft inserting nozzle.
Many kinds of weft detaining devices have already been proposed and put into practical use. Of these, there is a drum type one which has been proposed by the inventors one of who is the same as in the present application and is disclosed in European Patent Application No. 80104480.1 entitled "Shuttleless Loom Weft Detaining Device". This drum type weft detaining device is constructed and arranged as follows: A rotatable drum is provided between a weft yarn supply device and a weft inserting nozzle, which drum is formed with a frustoconical section whose diameter gradually decreases in the direction of the weft inserting nozzle, and a cylindrical section integral with the frustoconical section. Additionally, the rotatable drum is provided with a first weft catching member located in the vicinity of the border of the frustoconical and cylindrical sections to catch the weft yarn at least for a period of weft picking in timed relation to the operational cycle of a loom, and a second weft catching member located at the cylindrical section to catch the weft yarn for a period except for at least the weft picking period in time relation to the loom operational cycle.
With this arrangement, the weft yarn in a length required for each weft picking is wound around the cylindrical section between the first and second weft catching members. Accordingly, the weft yarn can be smoothly drawn out from the drum during weft picking, so that an appreciable resistance is not applied to the weft yarn being drawn out during the weft picking, thereby preventing the weft yarn from being cut. However, a further improvement has been expected to the abovementioned drum type weft detaining device, because the first and second weft catching members and a device for operating them must be disposed within the rotatable drum whose inside space is not so large. This unavoidably restricts the freedom in selecting the size and construction of the weft catching members and the operating device therefor, accompanying with problems in which it is troublesome to adjust the operational timings and to make maintenance of the weft catching members and their operating device.